Crazy SpaceX Moon Plan? Program Evaluation by U / S_Hirangy (reddit)

Vyacheslav Ermolin, May 3, 2020.

What are you talking about?

Space lovers over the past couple of days have heard and read a lot about the epic victory of progress over retrograde. NASA has chosen SpaceX (in a company with two others) in a competition for commercial companies to create a lunar lander.

In Trump’s ambitious Artemis program (returning to the moon on the 24th), the lunar landing module was an element that has not yet been launched. The booster has been defined for a long time - this is SLS. Spaceship to fly to the moon and return to Earth - Orion. Their construction is in the final stages. The take-off and landing lunar module was in the process of selection. NASA decided to resort to its successful experience of attracting private firms to develop rockets and ships for the ISS. She identified three winners of the preliminary competition - Blue Origin (in cooperation with others), Dynetics (also in cooperation) and SpaceX (alone).



One billion dollars was allocated for drawing pictures and making demonstration models. In February of the 21st year there will be a debriefing and a choice of the performer.

Of course, the most impressive and amazing size was the proposal from SpaceX, which suggested using its new generation rocket system (fully reusable). With Moon-adapted Starship option. Here he is handsome (astronauts in a cradle on ropes):



The Artemis program itself, in the latest available version, now looks like this:



SpaceX enthusiasts and astronautics lovers around the world vividly joined the discussion of this news. And some even made preliminary calculations for the proposed flight scheme.

One such enthusiast turned out to be a Reddit member, U / S_hirangy
Link to his post.

I translated the picture for clarity (see above).
The original infographic is like this.



He made a preliminary preliminary calculation of the necessary fuel for the program of the first astronaut landing on the moon. And an estimate of the number of starts of the Starship-Super Heavy system from Earth.

It turned out that using known data (from SpaceX and Ilon Mask) about the system’s parameters, it would be necessary to make 35 (!) Launches of a superheavy rocket to land from the lunar orbit to the surface of the moon and return two American astronauts back to the orbit. The weight of a fully fueled rocket at the start was accepted by him 4,500 tons (although SpaceX has not decided on the final weight, which “walks” from 4 to 6 thousand tons). Those. it will be necessary to launch almost 160,000 tons of fuel and steel for landing on the moon (not delivering to it, but only landing) of two 100 kilogram astronauts, as always written in the American press of “the first woman and one more man”. In addition, it will have to do 33 docking and refueling in orbit of the Earth and the Moon.

Calculation is available here. And his picture.



I cannot evaluate the accuracy of the calculation and the assumptions made on the basis of the initial data. This can only be considered as a preliminary assessment. For example, in the calculation for fuel in orbit, the weight of 100 tons is assumed (this is the weight of the Starship payload from the SpaceX document). In the table, you can substitute other values ​​and see what happens in the end. With a weight of 200 tons of fuel in a tanker, instead of 35 starts, only 20 turns out. Radish horseradish is not sweeter.

In my amateurish opinion, it is difficult to imagine a more insane and unrealistic project. I admit that the calculation was performed incorrectly or there are unaccounted factors. But numbers and parameters have appeared and will be discussed. I would like to see alternative calculations
(if any).

For interest, I translated the Starship User Guide
can be downloaded here.